Abstract
A new seismic retrofitting method reinforcing the termination zone of the longitudinal bars of RC bridge pier in which reinforcing members were placed only two-sides of the pier and enables to retrofit without removing machine room under viaduct was developed, and its flexural reinforcing effect was clarified. Beam tests were carried out using RC beam specimens in which two-sides of the existing beam were retrofitted by fixing RC reinforcing beams with anchor bars. From the beam test results, it was clarified that the ratio of the load carried by reinforcing beams to the load carried by existing beam was proportional to the products of the ratio of the rigidity of reinforcing beams to the rigidity of existing beam and the ratio of reinforced length within shear span to the effective depth of existing beam. Cyclic loading tests were also carried out using model pier specimens of the actual pier structures of the Touhoku-Shinkansen, in which the new seismic retrofitting method was expected to applicate. From the test results, it was clarified that the damage at the bar cut-off sections of the pier, in which failure mode factors S before retrofitting were under 1.0, could be avoided by reinforcing two-sides of the pier with RC reinforcing members such that the failure mode factors S' after retrofitting were about 1.3.
